Author Topic: Optical illusion  (Read 5330 times)

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Offline TimBo

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Re: Optical illusion
« Reply #15 on: February 06, 2018, 09:53:36 am »
It doesn't look like your bow has this issue, but sometimes a bit of propeller twist can cause that sort of optical illusion. 

Offline jeffp51

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Re: Optical illusion
« Reply #16 on: February 06, 2018, 10:53:27 am »
Never mind what it looks like.  You should focus on how it feels when it is being drawn

I hear this from a lot of the really experienced bowyers, but as I still feel like a newbie some days, I really am not sure what it means.  What exactly am I trying to feel?  I don't have a mirror big enough to look at my draw in, and getting someone to take a picture is difficult, especially when most of my scraping happens when others are in bed.  Which leaves me with the tree.  So what exactly is good tiller supposed to feel like?

Offline Marc St Louis

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Re: Optical illusion
« Reply #17 on: February 06, 2018, 11:02:44 am »
Never mind what it looks like.  You should focus on how it feels when it is being drawn

I hear this from a lot of the really experienced bowyers, but as I still feel like a newbie some days, I really am not sure what it means.  What exactly am I trying to feel?  I don't have a mirror big enough to look at my draw in, and getting someone to take a picture is difficult, especially when most of my scraping happens when others are in bed.  Which leaves me with the tree.  So what exactly is good tiller supposed to feel like?

Maybe you should re-read this thread http://www.primitivearcher.com/smf/index.php/topic,62531.0.html
Home of heat-treating, Corbeil, On.  Canada

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Offline aaron

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Re: Optical illusion
« Reply #18 on: February 06, 2018, 11:17:14 am »
Mark, I just read the  "balance in tillering" thread again. With this in mind and your statement "never mind what it looks like", would you say that when you hand draw a bow, you are trying to feel if the handle is pulling more towards top or bottom? That is, you don't need to see it because you can feel that the limbs are unequal due to unequal pressure of the handle on the hand?
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Offline jeffp51

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Re: Optical illusion
« Reply #19 on: February 06, 2018, 11:29:08 am »
Marc, I did read that thread, and it is part of why I raise my question.  I can see the tilt in the picture, but how would you feel that in the hand? He may just as easily be aiming differently or holding the bow a little different.  I assume that it is just because I have only made a dozen bows or so, and with more experience, maybe I will feel it better, but right now, I don't feel anything.  What should I be feeling for?  I can imagine some sense of balance, but you can't feel a stiff spot mid-limb, can you?

Don't get me wrong,  your bows are gorgeous, so I know you know what you are talking about. I am just not sure where I should be focusing my attention.

Offline bradsmith2010

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Re: Optical illusion
« Reply #20 on: February 06, 2018, 12:03:14 pm »
at first glance looked good to me,, about the never mind how it looks,, hmmm ,,, Im not sure that is exactly right,,
if the taper is even on the bow,, like a character stave,, the tiller may not look even,, althouh the limbs are working evenly,, then if the bow shoots great,, with perfect arrow flight,, then the look of it would be secondary to the way it performs,, but you are still looking at it,, if the bow is shooting great and maintaining a good unbraced profile,, then making it look different in the tiller if probably not gonna make it better,, (--)

Offline Marc St Louis

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Re: Optical illusion
« Reply #21 on: February 06, 2018, 04:43:51 pm »
Mark, I just read the  "balance in tillering" thread again. With this in mind and your statement "never mind what it looks like", would you say that when you hand draw a bow, you are trying to feel if the handle is pulling more towards top or bottom? That is, you don't need to see it because you can feel that the limbs are unequal due to unequal pressure of the handle on the hand?

Yes that is correct

Marc, I did read that thread, and it is part of why I raise my question.  I can see the tilt in the picture, but how would you feel that in the hand? He may just as easily be aiming differently or holding the bow a little different.  I assume that it is just because I have only made a dozen bows or so, and with more experience, maybe I will feel it better, but right now, I don't feel anything.  What should I be feeling for?  I can imagine some sense of balance, but you can't feel a stiff spot mid-limb, can you?

Don't get me wrong,  your bows are gorgeous, so I know you know what you are talking about. I am just not sure where I should be focusing my attention.

You can feel a when a limb is stronger than the other but that won't tell you if a limb is tillered poorly.  You won't be able to feel the bow tilting if you have a death grip on the handle.

at first glance looked good to me,, about the never mind how it looks,, hmmm ,,, Im not sure that is exactly right,,
if the taper is even on the bow,, like a character stave,, the tiller may not look even,, althouh the limbs are working evenly,, then if the bow shoots great,, with perfect arrow flight,, then the look of it would be secondary to the way it performs,, but you are still looking at it,, if the bow is shooting great and maintaining a good unbraced profile,, then making it look different in the tiller if probably not gonna make it better,, (--)

A backed bow is usually pretty uniform in the way it looks but there are always exceptions to every rule
Home of heat-treating, Corbeil, On.  Canada

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Offline jeffp51

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Re: Optical illusion
« Reply #22 on: February 06, 2018, 04:49:26 pm »
Thanks Marc, that is helpful.

Offline Lumberman

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Re: Optical illusion
« Reply #23 on: February 06, 2018, 05:11:16 pm »
Thanks for asking, something I was wondering as well and was puzzled by this past weekend. Flipped it a few times and then figured it must just be in my head

Offline Louie

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Re: Optical illusion
« Reply #24 on: February 07, 2018, 02:16:57 am »
Thanks for all the feedback guys. You know, sometimes the mind can play tricks and completely shake your confidence. This is my second bow, but really my first real bow. I made one out of cheap pine just prior to this so I can get a feel for the tools I needed to use. Pine is a NO NO for bow wood, I do know that, but heck, it was purely a practice piece, which actually came in at 26# at 27" and I shot about 50 arrows with it too, until I saw a compression fracture on the belly. Pine bow is now a wall hanger. I was worried I would over tiller this hickory/ipe one until I had a kids bow. Finished tiller now, bow comes in at 38# at 28". My goal was 40# at 28", so I'm pleased with the result.
Now to finish the handle and shoot some arrows.

Some pics of the pine bow.
One of the greatest paradoxes of your physical senses, is that your eyes actually show you what you believe, not what you see.

Offline Del the cat

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Re: Optical illusion
« Reply #25 on: February 07, 2018, 02:25:24 am »
You may find the actual tiller rig isn't set up true.
Just 1/8" out and it can cause the effect you are mentioning.
I have the bow resting on a curved block so that it can rock, some people prefer a square block which stops the bow slipping off.
Anyway, it's better (IMO) to support the bow where it will be getting hand pressure and draw the string from where the fingers will pull it. This set up is not symmetrical but it better represents how the bow will be used.
Have a lok at this post from my blog:-
https://bowyersdiary.blogspot.co.uk/2013/03/tillering-symmetry.html
it may show what I mean better.
Del
Health warning, these posts may contain traces of nut.

Offline PatM

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Re: Optical illusion
« Reply #26 on: February 07, 2018, 06:35:25 am »
The length of your bow and the materials used make it a good candidate for piking to gain weight.

Offline burchett.donald

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Re: Optical illusion
« Reply #27 on: February 07, 2018, 07:08:25 am »
     Looks like its time to shoot some arrows...I like the slightly positive upper here...I think you may be over thinking this...How does it shoot...It is hard to detect a slight imbalance in hand especially a heavy bow...You look balanced from here...See how it feels loosing an arrow...You look low wrist, nothing wrong if this is your style...2nd bow A+...
                                                                                                                         Don
Genesis 27:3 Now therefore take, I pray thee, thy weapons, thy quiver and thy bow, and go out to the field, and take me some venison;

Offline George Tsoukalas

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Re: Optical illusion
« Reply #28 on: February 07, 2018, 07:53:29 am »
Well, I've seen that also, Louie.

I use a rope and pulley and do not support the bow.

I tiller from the center.

Nothing approximates how it feels in the hand.

Is the bow tilting or is the handle pressure even? Those are questions I ask myself every time  I take the bow down from the rope and pulley and test with short pulls.

I finish tiller with a digi pic taken by my wife or daughter.

Also, I use my patio window at night. Gives a nice reflection.

I like the tiller even or bottom limb slightly stiffer which you appear to have.

Looks good to me.

Jawge

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If you ain't breakin' you ain't makin!

Offline Springbuck

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Re: Optical illusion
« Reply #29 on: February 07, 2018, 05:47:39 pm »
 "Do you guys suffer from this optical illusion sometimes?"

Yup, all the time.  Less so in laminated bows.  Propeller twist can be caused by making the limb thicker down one side.  This often happens to me just because of how my bow rests in the vise, where I have to stand, and how I hold my tools.   Something to watch for in the future.  Read the Sticky thread above about limb-tip lean and twist caused by this.

  One thing that taught me about how to "feel" a bow in the hand is purposely pulling the string from way above and way below where you really WOULD to shoot an arrow, while leaving your bow hand in the right place.  If your bow is balanced, pulling the string from too high will make the bottom limb feel week and the bow's upper limb will tip back toward you, and vice-versa.

Once you are familiar with the feel, try pulling an unfinished bow from the correct points on handle and limb.  A weak upper limb will lean the bow away from you and vice-versa.